Dry powder dispersing device



Aug. 11, 1959 c. R. WEINERT DRY POWDER DISPERSING DEVICE Filed Dec. 28, 1956 iii INVENTOR. Carl R. Weiner/ HIS ATTORNE Y5 United States Patent DRY POWDER DISPERSING DEVICE Carl R. Weinert, Pittsburgh, Pa., assignor to Federal Laboratories, Inc., Saltsburg, Pa., a corporation of Pennsylvania Application December 28, 1956, Serial No. 631,095

"13 Claims. (Cl. 222- 82) The present invention relates to a dry powder dis persing device primarily adapted for blowing tear gas dust into the surrounding air to generate clouds of tear gas. This device is preferably installed on a hand truck or motor truck for portability and readily operates either while retained in a temporarily stationary discharging position or while moving with the truck thereby leaving a wall of the dust suspended in air.

According to a feature of the invention a source of compressed gas is carried by the truck above indicated and is connected to the dispersing device to circulate a propelling draft of gas therethrough in a manner to agitate and cause the dust to lift to a point where it will be carried out of the container in the draft of escaping gas. A further feature'is that a sealed can holding the dust may be loaded intact in the present device and repose indefinitely in readiness therein in that fashion to keep an effective charge in the device at all times, but without the danger of the powder caking or deteriorating due to exposure. The device according to this invention is internally provided with built-in can puncturing means and further incorporates mechanism which in conjunction therewith causes the can to be punctured in its stored condition in a simple positive operation transforming it to immediate use. Following each use the device is reloaded with a fresh can of powder and spent cans are discarded and replaced with the fresh ones as fast as emptied. Test results show that a sustained running time of approximately seconds is all that is necessary for the compressed gas to completely empty each can.

As above indicated the present device is primarily adapted for dispersing a cloud of tear gas dust but the general structure and working principles thereof have equally important application in other dry spray operations where gas-entrained particles of differing compositions useful as fire-fighting chemicals or surface coating materials or the like are applied by blowing them on or into areas to be treated.

Further features, objects and advantages will either be specifically pointed out or become apparent when for a better understanding of the invention reference is made to the following description taken in conjunction with the accompanying drawings in which:

Figure 1 is a view in elevation, partly in section, of a tear gas system embodying a preferred form of the present invention;

Figure 2. is a top plan view;

Figure 3 is a detail taken along the section lines IIIIII of Figure 2;

. Figure 4 is a view corresponding to Figure 1 but showing a modification of the invention;

Figure 5 is a perspective view showing a detail of manufacture pertaining to the modification of Figure 4.

'In Figures l-3 of-the drawings, a gas operated, powderdispersing device is illustrated having a thick Walled pressure cylinder 10 of metal which is closedby an into- 2,899,106 Patented Aug. 11, 1959 gral bottom wall 12 and which carries a thick circular head cover 14 fitting the mouth of the cylinder 10. Adjacent that mouth, the cylinder 10 carries threaded studs 16 arranged in a ring and having companion hold down nuts which fit down on the complementary ring of bolt holes 18 in the attaching flange of the cover 14 so as to firmly clamp against a seal 20 to form a gastight joint with the mouth of the cylinder 10. An upstanding pad eye 22 integral with the cover 14 receives a cross bolt 24 pivoting the device to a pair of fork arms 26 form-ing part of the bracket mounting structure 28 of a wheeled truck which also carries a valve controlled gas cylinder 30 of conventional construction charged with dry nitrogen or with dry air under the usual commercial pressures maintained on gas of this character. For example, satisfactory results have been obtained with 2000 psi. initial pressure in the gas cylinder 30.

A free piston 34 fairly loosely fitting in the cylinder 10 has a cylindrical shaped skirt 32 which rests on the bottom wall 12 so as to enclose a working chamber 36 and further has an integral piston head 38 forming a shiftable transverse wall in the cylinder supporting a sealed can 40 of tear gas powder 42. The can 40 is a conventional metal can of selected capacity which, for

. example, corresponds to the one gallon paint can size,

and the body of tear gas dust or powder 42 therein is of a light, dry consistency weighing 1 kilogram for the size can in the case just specified and which, in that case, will contain approximately 730 grams of chloracetophenone as the tear gas agent.

A set of can puncturing tubes 44, 46 and 48 with bias-cut ends is arranged at the head of the pressure cylinder 10 with their sharp points inwardly directed from the inside face of the cover 14 so as to confront the top of the can 40 and being fixed with their upper ends cut off squarely and threaded into the cover 14. The tube 44 intersects a horizontally drilled nozzle-like orifice 50 in the head of the cover 14 which operates as a side discharge outlet when the head of the can punctures on the tube 44 in the dotted line position 40a of the can. In this punctured position of the can, the tube 48 functions as a supply inlet, being connected to a horizontally drilled supply passage 52 in the cover 14. The tube 46 (Figure 3) threads through the cover 14 and the external threaded extension thereof carries a jam nut 54 snug against the outside of the cover 14 and a safety disk retaining cap 56 forming a safety outlet. The cap 56 has a center opening and surrounds a metal shear ring 58 to clamp to the end of the tube 46 a frangible safety disk 60 which effectively seals and resists the working gas pressure, but which ruptures under excessive pressure enabling the gas to escape directly to atmosphere through the tube 46. In the latter case, the center opening in the cap 56 forms a supplemental discharge outlet directing a jet of the escaping, dust laden gas directly upwardly.

A longitudinal gas diverting passage 62 in the wall of the cylinder communicates at one end with the supply passage 52 for tube 48 through a short indexing sleeve 64 disposed partly in the head 14 and partly in the cylinder 10 and fixed to the latter so as to register with a preformed opening in the seal 20. At the lower end the diverting passage 62 communicates With a port 66 in the wall of the cylinder at a point where the depending cylindricalskirt 32 of the piston normally covers and blocks it. A flexible rubber hose 68 has opposite end connections to the valve of the gas cylinder 30 and to a fitting 70 threaded through the bottom 12 of the cylinder so as to communicate with the working chamber 36.

In operation of the device of Figures 1-3, the valve on the charged gas cylinder 30 is twisted open by hand admittin'g gas into the working chamber 36 to drive the piston upwardly with the necessary travel to puncture the top ofthe can 40, the necessary puncturing thrust being approximately 50' pounds according-to test data. The predetermined final travel of the piston is the motion suffi; c'ie'nt to uncover the. port: 66 and introduce a stream of g'asi'nto the diverting passage 62. The draft of gas emits from the inlet tube 48 and. circulates in. the can across the top surface of the'bo'dy ofpowd'e'r'42 so asto agitate and lift the particles with the result that dust laden' gas escapes through the discharge outlet 50 having the tear gas agent entrained therein. The pressure drop in the diverting passage 62' isisufiicientito insure that the work'- ing'p'ressure'in thecan' 40 and. in the cylinder space thereabove'never exceeds" the pressure in the working chamber 36'therehypreventingi the piston from" huntingor' retracting after it initially'jumps and reaches its uppermost position; As an example, 100'p.s.i; working pressure in' the can 40is sufficient to mix in the dust therewith and the design strength of the safety disk 30 is such that it will rupture at approximately 250 p.s.i. Rupture strength. of the pressure cylinder 10* is designed, of course, for withstanding several timesthis amount of pressure. and in case the orifice forming the" discharge outlet 50'is accidentally or maliciously stopped up, the disk 30 will be the first thing to rupture and relieve the internal pressure without damage tothe device:

The gas cylinder 30" can be shut off at will, enabling thepressure in the working chamber 36 to'dissipate', thus collapsing the chamber 36 as the head 38 of the piston moves from the dotted line showing of Figure 1 into' the solid line position where the skirt 32 thereof reblo'cks the port 66; Thus the puncturing, emptying; and release of support from the bottom of the can 40 are completely automatic operations obtained by one movingpart, name- 1y, the pressure movable piston. Owing toitslarge diameter, the piston jumps with practically instantaneous re sponse to the in-rushing gas and inasmuch as approximately 5000 pound thrust is" theoretically available, it'will' be' apparent that the completed can puncturing operation takes only a moment;

In the modification of Figures 4 and 5', a pressure cylinder 110 in the device has a set of bias-cut tubes 44, 46, 48 of the same type'andpurpose as the preceding embodiment, and fixed in the head 114' thereof which may be integral with the cylinder structure. The safety outlet 56 and the discharge outlet 50 are the same as inthe preceding embodiment, but the gas supply fitting 70 which is connected through the hose" 68 to the gas cylinder 30, is mounted directly to the head; A sealed metalcan 40- of the tear gas powder 42 is shiftably supported at its lower end within the cylinder 110 by resting on theofiset face 13-8 in an end cover 140 which carries a flanged skirt 142 defining a socket or receiving recess for the can 40; Two diametrically opposed stay bolts 144 are anchored in aflange at the mouth of the cylinder 110 and have their heads 146 carried in a downwardly ofi'set position so asto retain a vertically slidable metal seal 48irr a guided relationship, A two-armed spider 150'has'enlarged' oppo site end portions each of which is transversely bored at 152 and counterbored at 154 soas to provide sockets for the heads 146 of the stay bolts 144. The metal ismaehined away from the enlarged end portions along the dotted lines 156 of Figure 5 so as to provide the side entry slots indicated at 1-58 in Figure 4 for ready detachment and attachment of the spider to the stay bolts 144. The spider 150 has a hub bore 160 threadedly' receiving a' jack screw 162 which carries a small hand wheel 164 fixed at the lower end. A retaining plate 166 carried by the end cover 140 closes the end of a socket formed centrally thereof so as to clamp therein a ball portion on the screw 162 to form a permanent swiveled unionconnection 168 between the cover 140 and the: spider 150 in which the jack screw is permanently retained.

In use, the modification of Figures 4 and 5 is loaded byintroducing the can 40' and placing the cover over the exposed end in an aligned position whereupon the spider is properly manipulated and the counterbores became interengaged with the head of the bolts 144. The wheel 164 is turned by hand to screw the jack screw 162 upwardly and the movement. of translation for shifting the can 40. into the. dotted line position. 40a where the tubes poke through the head thereof is the motion suflicient to clamp theseal 14& into; a; fluid tight jointtbetween: the end cover. flanged skirt 142 and the. mouth. of the pressure cylinder 110. During this movement the downward otfset of the face 138 compared to the full length ofthe can 40' enables the can to extend at all times partly into the cover 40- andLpartLy'into the pressure cylinder 110 so as to guide the cover in cooperation with the ball and socket swiveled union connection 168 and insure that the free end of the skirt 142 squarely engages. the mouth of .the cylinder III); The draft of gas from. the cylinder 30'when the valve thereon is twistedopen'entersthe can. 40 through the puncturing tube 48 so. as to agitate and lift the entrained. dust 42 which thereafter is caught in the draft and dispersed with the escaping gas.

In installing. each of the devices of thepreceding emhodiinents', a point selected fon mounting. it may, for example, be onthe rear bumper of the wheeled truck ihdic'ated or other convenient external point at which the bracket mounting, bolt 24' is not less than 2 feet or. more than 4 feet. fromthe' ground and an operator side the truck controls. the valve on cylinder 30 to release the dust. 42 into the surrounding, air as. one continuous continuous. blast or. intermittently at will, test results showing that 10' seconds. total running. time is required to. release the full'. charge. Eachcylinder 30 contains a standard commercial charge of gas sufiicient to discharge. the one kilogram content of the dust 42, and test results. show that a fully'charged cylinder should be used for. each; chit-$6,. the. pressure thereof from 2000. to 1400' psi. The. valve on the cylinder. 30. is. then closed and the cylinder. 30 is reconnectedto be recharged or. else 'a. fully charged. substitute cylinder. is used to-replace it. The punched holes. inthe. top of. the can. 40 of. Figure. 1 provide. a convenient means for grasping; and lifting the empty can; from the pressure. cylinder 10,, the. threaded. fasteners 16,, meantime, having been released by hand to. enable. the. cylinder. and the cover 14 to be. separated. There may be a slight tendency in some cases for the can to stick on the tubes of Figures 1 and 4,. but. sticking is. obviously no. problemin. Figure 1 and in Figure 4 the can dotted line position 4011 extendsat. one end. at all-times beyond the corresponding end of. the mouth of .the cylinder 110.- and this extending end can readily be removed by hand, the cover. 40, meantime. having. been: freed and detached from the pressure. cylihder. 110.

Variations within the spirit and: scope of the invention. described are equally comprehended by the foregoing. description.

L claim;

1.. In. a gas. operated device for dispersing tear. gas. dust, a pressure cylinder having can puncturing means at the top. end and cansupporting'means forming azmovable wall. chamber within the pressure cylinder at: the other end, means for causing relative movement between; the can puncturing means and. the can supporting: means to puncture an' interposed can. of dust,.inleti and outlet passsage means connected to said can puncturing means to. cause a draftof. working. gas to circulate becoming dust laden between entering and leaving the top of. the earn. and. twofdifierently restricted supply and diversion passages: jointly communicating with. said. movable wall: chamben said. supply passage constituting; the relatively free one ofithe two passages tofreely communicateworke ing pressunm released. from a. source OfxCOlIlPIfCSSCi t me and freely deliver same into said movable wall chamber, whereas said diversion passage being the relatively restricted passage and connected to said inlet passage to insure an intervening pressure drop upstream of the can puncturing means thereby preventing working pressure in or about the interposed can from exceeding the pressure in said movable wall chamber.

2. A dispersing device having a discharge outlet,'pressure movable means at the opposite end of said device from said outlet for supporting and shifting a container means into a position for discharging the contents thereof through said outlet, and means through which working pressure is introduced and applied in one stream to said pressure movable means to motivate same and substantially simultaneously communicated to the container means for discharging the contents in the above described manner, there being valve surface portions operatively disposed between said, pressure movable means and a portion of said pressure introduction means in communication with the container means, and establishing cooperation to automatically open the latter said portion in timed response to movement of said pressure movable means.

3. A dry powder dispersing device comprising a pressure cylinder having a discharge outlet, pressure movable means at the opposite end of said cylinder from said outlet for shiftably supporting a powder container therewithin in a raised position enabling the contents to be discharged through said outlet, means through which working pressure is introduced in a space between said pressure movable means and the adjacent end of the cylinder, and a passage connected at one end so as to operatively communicate working pressure to the container when in the aforesaid raised position and connected at the opposite end to said working pressure space in a position operatively controlled by and covered and uncovered automatically in response to movement of said pressure movable means.

I 4. A pressure vessel adapted to disperse material from sealed cans by discharging the contents thereof in a draft of escaping gas, comprising pressure cylinder structure including a cylinder and a removable end cover fitted thereto to define a can receiving space therewith and presenting an inside face for engagement with the can at one end, a discharge outlet formed at the head end of'said cylinder structure, means including a seal between the cylinder and fitted end cover rendering the vessel completely gas tight .to the escape of gas except from said discharge outlet, can puncturing means fixed in said inside face at the head of said structure comprising hollow elements arranged with inwardly directed points and one being connected to said outlet and another adapted to introduce a draft of compressed gas internally of the can, and can support means comprising a shiftable thrust member at the opposite end of said structure to create a driving force on said can for bodily lifting it in said space into an upwardly impaled position on said fixedpuncturing means.

5.A pressure vessel adapted to disperse material from sealed cans by discharging the contents thereof in a draft of escaping gas, comprising pressure cylinder structure including a cylinder and a removable end cover fitted thereto to define a can receiving space therewith and presenting an inside face for engagement with the can at one end, a discharge outlet formed at the head end of said structure and constituting the sole operative outlet from said pressure vessel which otherwise is secured together so as to be sealed completely tight against gas escape therefrom, can puncturing means fixed on said inside face at the head of said structure comprising hollow elements arranged with inwardly directed points and one being connected to said outlet and another adapted to introduce a draft of compressed gas internally of the can, means clamped between the cylinder and the fitted end cover forming a joint positively sealing the can receiving space within said structure so as to be completely sealed, tight in the above described manner, and can support means comprising a shiftable thrust member at the opposite end of said structure to create a driving force on said can for bodily lifting it in said space into an upwardly impaled position on said fixed puncturing means.

6. A device adapted to disperse material from sealed cans by discharging the contents thereof in a draft of escaping gas, comprising a pressure cylinder structure including a cylinder and a removable end cover fitted thereto to define a can receiving space therewith and presenting an inside face for engagement with the can at one end, a discharge outlet formed at the head of said structure, can puncturing means fixed to said inside face at the head of said structure comprising hollow elements arranged with inwardly directed points and one being connected to said outlet and another adapted to introduce a draft of compressed gas internally of the can, said can puncturing means including a third hollow element providing a safety outlet at its outer end and having a pressure confining disk clamped across the resulting passage leading internally from said element from the inwardly directed point thereof to said outlet and effective to rup ture only under excessive pressure therein to vent the structure safely to atmosphere, and means including a shiftable thrust member at the opposite end of said structure to create a driving force on said can for bodily lifting it in said space into an upwardly impaled position on said fixed puncturing means.

7. A device for puncturing and blowing a container empty under forced draft by causing the contents to be caught and dispersed in that draft comprising, a pressure cylinder which is closed at one end and which is fitted with an end cover and with interposed sealing means at the opposite end, means carried by the cylinder for holding the end cover firmly clamped upon the sealing means to seal the intervening joint gas tight, puncturing means at the head of said cylinder comprising sharp pointed tubes arranged with one of said tubes connected to discharge from the interior of the container into a fixed outlet, and another connected to an inlet passage and fixed to blow inwardly into the interior of the container, anda threaded joint included in said cover holding means enabling the cover to shiftably support the container Within saidcylinder, said cover being formed to present an offset supporting face for lifting the container upwardly thereupon in said cylinder whereby final lifting movement to puncture the container on said puncturing is the motion sufiicient to seal the joint.

8. A device for puncturing and blowing a container empty under forced draft by causing the contents to be caught and dispersed in that draft comprising, a pressure cylinder which is closed at one end and which is fitted with an end cover and with interposed sealing means at the opposite end, means carried by the cylinder for holding the end cover firmly clamped upon the sealing means to seal'the intervening joint gas tight, puncturing means at the head of said cylinder comprising sharp pointed tubes arranged' with one of said tubes connected to discharge from the interior of the container into a fixed outlet, and another connected to an inlet passage and fixed to blow inwardly into the interior of the container, and pressure movable means for supporting the container Within said cylinder from a position at the opposite end thereof and movable to lift the container through a distance sufiicient to puncture it on said puncturing means.

9. A device for puncturing and blowing a container empty under forced draft by causing the contents to be caught and dispersed in that draft comprising, a pressure cylinder which is closed at one end and which is fitted with an end cover and with interposed sealing means at the opposite end, means carried by the cylinder for holding the end cover firmly clamped upon the sealing means to seal the intervening joint gas tight, means at the head of said cylinder. consistingof an arrangement of sharp,, gas directing, elements adapted topoke'through the top of the container; and passage. forming, means in said device for connecting difierent ones. ofsaid elements to atmosphere and to a. source. of compressed gas, at. least one. of. said atmosphere. connected: passages beingiatalltimes free of obstruction.

10.. A device for puncturing, andblowing a. container empty under forced draft by causing the contents to. be caught. and dispersed in. that draft. comprising. a. pressure cylinder. which is closed at one end and which is fitted with an end. cover with interposed: sealing means at the opposite end, means. carried by the. cylinder for holding the end cover firmly clamped upon the sealing means. to seal the. intervening joint? gastight, a plurality ofpuncturing means for the sealed. container fixed at. the head of said pressure. cylinder, a gas inlet. passage. dis.- posed parallel to said cylinder and having; one end con? nected to one of saidpuncturing. means at. that end; of the. cylinder, means connecting the; other puncturing means to atmosphere, and. a pressure movablepiston: at the opposite end of the cylinder which shiftably supports the container therewithin. and which when subjected to working. pressure drives the container. ontothepuncturing means, the opposite end of the passage aforesaid terminating in said cylinder at a point. confronting the path. of the piston. stroke and being controlled. thereby such. that final movement of the piston to puncturethe. container is motion sufficient to cause the. full, flow of working pressure to be diverted into said. oppositeend of the passage.

11. Adry material. disperser comprising. a pressureicylinder having a discharge outlet, an end. cover for thecylL- inder having means carrying it at theopposite end from said outlet for shiftably supporting thereupon a. container of the material within the cylinder in a position for dis! charging the contents through said. outlet, said carrying means comprising stay bolts having their shanks an? ehored. in the adjacent end of. said cylinder, threaded means adapted to be rotated by ha 1 and having a swiveled union at one end to said cover, and a spider having a hub in which the last said means is permanently threaded and having radial arm portions in which. intersecting slots and bolt receiving sockets are formed enabling. said portions to disengageably straddle the bolts. individually with the head socketed therein, and means for introduc- Sing a draft of pressure fluid into. said container when itv occupies the aforesaid discharging position, saidcy-l; inder and said end cover having confronting flanges which engage to form a sealed joint therebetween. and arranged whereby final movement of they latter for shifting the container into the discharging. position in the cylinder is the motion sufficient to clamp said: joint fluid tight.

12. A dry material disperser comprising: a pressure cylinder. having a discharge outlet, an end cover for. the cylinder having means carrying it at the opposite end from said outlet for shiftably supporting thereupon a container of the material within the cylinder in" a. position for'discharging the contents through said outlet, said carryingmeanscomprisingstay bolts havingtheir shanks anchoredin. the adjacent. end ofsaid cylinder; a spider haviiig, arms radiating from the hub portion thereof and detachably connected to the heads of stay bolts, said cover having a downward ofiset face to support said container whereby the container extends partly within said cover and partly within said cylinder at alltimes, androtatable. means carried on threads in the hub of saidispider and operatively'connected with the cover on the side thereof opposite to 'said container so as to cooperate therewith in centering and guiding the cover upwardly under appropriate rotation of the just named means.

13. A gas operateddevice for automatically puncturing and dispersing the contents of a can in the form of gas-entrained dust, said device comprising pressure cylinder structure including a removable end cover fitted to the head of the pressure cylinder to define. a" can receiving space therewithin and presenting an inside face for engagement with the can at one end, individual can puncturing means fixed to the cover comprising hollow elements presenting points protruding through said inside face, one of said hollow elements providing a' safety outlet at its outer end and having a pressure confining disk contained in the resulting passage between the point on said element and said outlet and effective to rupture only under excessive pressure therein to vent the cylinder to atmosphere, a main discharge outlet formed in said cover and connected to another hollow element, a piston having a head arranged to support a can of the material at the opposite end of" said cylinder from the cover and havinga skirt slidably received in said cylinder, a-fitting in the'end of the cylinder adjacent said piston for introducing' working pressure into the chamber defined by the skirt thereof so as to lift the can upwardly inthe cylinder for puncturing it, from an initialposition, and a longitudinally extending passage in the wall of the-cylinder having a port at one end closed by" the. skirt of' the piston in said initial position and being connected at: the opposite end to oneof said hollow elements fordelivering said working pressure into the punctured. can incident to final puncturing movement of the piston whereby the skirt uncovers said passage; I

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